At present, in order to improve safety performance of the battery module, a vent plate is generally provided on a cap plate of a battery cell that constitutes the battery module, and a large amount of high-temperature and high-pressure gas generated at the instant of failure of the battery cell is released through the vent plate.
Especially for a battery cell structure in which two output poles of the battery cell are arranged opposite to each other (i.e., the two output poles are not in a same plane), a vent plate is provided on a cap plate of each output pole. That is, both cap plates of the battery cell are provided with the vent plate. The installation of the vent plate can improve the safety performance of the battery cell to a certain extent. However, when such a battery cell is applied to a battery module, especially when applied to a battery module having its output poles at a same side, it may be difficult to form an external short circuit for the battery module to fuse a charging circuit of the battery module and thus prevent overcharge of the battery module when the overcharge occurs. Therefore, there is a potential safety hazard. It may be impossible to ensure the safe use of the battery module, and may easily cause damage or explosion of a part or all of the battery cells.